Hypodermic needle



Patented June 20, 1950 l 2,512,569 l -HYPODERMIC NEEDLE Jacob Saflix',l Los ngeles, Calif. "Application september 26, 1 947, serial No. 776,291

y y invention.y relates to the art of hypodermic injection devices.V More particularly it .pertains to Ahypodermic Vneedles or cannulae which are adapted -to administer therapeutic substances bysubcutaneousv or intramuscular i.n.,v

jection. Similarly it pertains. to devices adapted for withdrawingsamples from any portion of the animal system, such as, -for example, blood from -a vvein or uidfrom the abdomen.

4In its preferred embodiment this invention isy directed Yto-a yhypoderrnic ycannula 'which af- V-fordsan optimum condition of vsharpness at its pointed or vpiercing -end or piercing Yrends, for greater facility and-ease in making an entrance into-the *skin and-.underlying tissues,which, of course, means less pain and discomfort to a patient during the injection and after the injection. vl v :Heretofore the-only materials that were considered .for the manufacture vof hypodermic needles were those that had the physical properties required for producing a sharp edge, such as steel or stainless steel, from which materials the greatest proportion of needles are made at the present time-and this in spite of the fact that these materials have some decidedly unsatisfactory physical properties. For example, brittleness, opacity, ready oxidization under certain conditions, and, usually, high cost of production which necessitates their being used over and over again. 1

.Whenv a needle is subject to reuse, it should be sterilized. This. requires time. Frequently, too, theneedle loses some of its sharpness, its

`point becoming duller with each `use and steriliaation. A dull needle causes considerable pain.

The needle described hereis one which is quite inexpensive and vcan be discarded after every use, thus eliminating much pain, the possibility of infection from lack of sterilization or betic has an inexpensive needle he can afford to discard at `will, Whose sharpness is dependable and Whose sterility may be insured at its source.

. 401mm. (o1. 12s- 1221) Brittleness,l also, is a most annoying and :often very serious matter in the hypoderm-ic medication art. Needles f break with great lregularity and surgery` is often required for the, removal of fragments. Sometimes a piece of broken, needle may be in such a position that it must be allowed to vremain in situ because of the, surgical diculties involvedin its removal; v -v OtherAv metals have4 othery disadvantages.-` An example of where afine material for hypodermic needles has been practically abandoned. because of inability to hold a sharp edge is pureplatinum, as well as purey gold.

With this invention, a non-metallic substance that is not brittle and 4therefore not -readily frangibleand which need not beV opaque or readily oxidizable, can be used, even though it, by itself, may not be able to receive or--maintain a sharp piercing or cutting edge. v v f This invention contemplates a cannula having a cutting or piercing edge of a material that canbe sharply formed and` a bodyportion of a softer, less frangible material.

Other objects, advantages, and features .-ofjthe invention willbecome apparent from thefio-llowing descriptionA read inf-,connection with' the accompanying drawings in which .similar elements are designated-by like numerals.

Figure 1 isa -longitudinal section of a needle with a hub for attachment to a -Luer type syringe. f j' Figure 2 is a longitudinal section of thefinjection end of a needle embodying this invention.

Figure 3 is a side elevation of the needle illustrated in Figure 2.v f Y Y Figurefl isa longitudinalv section of the injection end of aneedle showing another modification of the invention. e

Figure 5 is a side elevation of-the needle illustrated in Figure 4.

Figure 6 represents a cross sectional r.view taken along the line A-B in Figure 4. l

Figure 'l is a longitudinal section rof .the .injection end of a needle showing still another modification of. the invention. Y

Figure 8 .represents a cross` sectional. view taken along the lines C.-.D in.,Figure.'Z.. n

FigureB is a side elevation of the .needle shown in Figure 7. y

Figure 10 comprises alfragmentary longitudinal. section of van additional modication vof` the invention.

Referring more particularlyto the {featuresfof invention ,embodiedin the Amodifications shown by thevariousgures of the drawing, needle 2,512,569 Q-L .fr

At 4, the needle tip 2 is imbedded in the resinl ous portion 3. An opening 5 is providedthrough 'i which fluids travel. can be made of any hard metal such as stainless steel or the austenitic typeof nietaL'or iridium.. It can also be made of a synthetic resin which is hard enough to hold a good edge such as the allyl alcohol series of resins or the polyester type of resins or the phenol-formaldehyde group or the urea group and othertypes of resin.

The injection end of these needles, such as 2 inFigure l or 10 in Figure 2, etc., may also be made of the same resin as the body part by adding a hardening or reinforcing agent. 'A good example is glass fiber, a, synthetic resin fiber, o1' any other type of nber or filler which causes a 'change in the physical properties of the resin so that it will take Va. sharper, more pointed end adapted for piercing and penetratingr the skin and the adjacent underlying tissue.

If fibers of glass are used, the length and dimensions of the iibers as well as therconcentration may be subject to substantial variation, dependent upon the properties contemplated and the procedure involved in fabricating the cannula.

For optimum results concentration of glass fibers should not 'materially exceed 35% relative A'to 'the resin content. Optimum -concentrations are from 3% to 25%. The optimum dimensions of the glass bers include a, length in the approximate range ,of ge" to 1&4" and a diameter in the approximate range of 0.00022" to 0.00048." There may, of course, be a variety of other sizes and diameters used with fair results.

In Figure 2, the opening 9 of the cannula is on the injecting andk piercingend ID of the needle,

'the' latter being designated as a resin or plastic and containing reinforcing material, such as glass iibers I', dispersed therein. At I I is the area of attachment of the harder sharpened portion Il! Vto vthe softer, more flexible portion I2, likewise 'derived from plastic or resin.

Figure 3 illustrates the side elevation of the cannula illustrated in Figure 2. The sharpened anterior portion I0 joins the softer body portion I2, through the expedient of prongs II', thereby providing the said jointure I I.

In Figure 4 a cannula is illustrated whose piercing end II is beveled considerably and the most forward end I8 is of hard material adapted for and sharpened to a fine point. This hardened portion is embedded in the plastic or resin body I9 of the cannula through the expedient of prongs 2D', thereby providing the jointure 2U between the said body I9 and the needle end I'I, I8 which is 'shown as metal. e

Figure 5 is a side elevation of the needle shown in Figure 4, indicating the approximate positions of the metallic end I8 and resinous portion IS and the junction, area 20.

Figure 6 illustrates a cross section of this same needle shown in Figures 4 and 5,:the cross section rbeing along the lines A'-`B' in Figure 4. "The The sharply pointedV tip 2y vline C-D in Figure '7.

metallic or hardened portion I8 joins the softer resinous portion I9 at the junction point 2D.

Figure 'I is a needle or cannula whose Walls 2t are composed of a resin. Imbedded in one of the walls at 21 is a thin hard wire-like body which protrudes through the extreme forward portion 28 of the bevel of the needle and cornes to a very sharp piercing point 29. rThis point is so fine and sharp that it easily penetrates the skin and starts a small opening throughr which the 44:rest of the needle can expediently follow.

Figure 8 is a cross section taken through the Here is illustrated the imbedded member 2l in relationship to the lumen 30 of the needle and the walls 26.

'Figure `9 isa side elevation of the same needle l. shown 'in *Figures-'7.' and 8. Slightly protruding `give the piercing tip theI desired amountofhardness for tissue penetration. Accordingl'y'fthe pointed end of the needle comprisingthismodiiication is a plasticjsuch as `a synthetic "resin, reinforced by metal electrolytically. "deposited thereon. However 4as indicated hereinaboveyfthe end portion of the'needle may comprise 'other reinforcing expedientsattainable from materials other than a synthetic resin alone, as" illustrated by an organic synthetic resin containing lglass bers or other suitable nller material.

` Thus in the modification of Fig. V1Oth`e hollow tubular body Aportion'tl ofthe needle comprises-a resin or plastic, and the endI 32 thereof "is'similarly shown as being of resin or plastic derivation.` As a Areinforcing Y expedient,` said piercing end 32 is provided with a metal coating 33", which is desirably electroplated thereon.

It is understood that where a, needle or cannula is provided with two piercingends, both these ends may incorporate these teachings.

Pursuant to the drawings pertaining ,to vthe various modifications of the invention, the' needle may comprise a hollow' substantially rigid tubular body desirably of uniform cross section, with the end portion thereof, which may comprisea separate member, being permanentlyattached thereto and tapering in an oblique directionfrom the needle outlet to the sharp edge or piercing and penetrating point thereof. ,It will however be understood that the details and characteristics pertaining to the needle may be subject to areasonable element of variation within the purport and scope of the invention.

While I have described my. invention in accordance withv desirable embodiments it is'obvious that many changes maybe made in the details of construction and in the combination ofparts and materials, without departing from .the spirit of the invention as defined inthe following. claims.

I claim: n

l. An integral hypodermic needle of uniform cross section except for the extreme end thereof comprising a hollow substantially rig-id tubular body of a plastic material, saidneedle'having an end portion of. material otherthan' plastic alone and being harder than said tubular body, said end portion being permanently aixed to the hollow tubular body andjprovided with asharp edged point adapted to pierce andpenetratej the slain and adjacent underlying tissue, lthe inner surface oi'thesaid end portion being in'flush alignment with the inner surface of the said hollow tubular body, said end portion, at least in part, tapering in an oblique direction fromv the needle outlet to the piercing :and penetrating point.

2. An integral hypodermic needle as in claim 1, wherein the hollow tubular body is of a synthetic resinous material, and the end portion comprising the sharp edged point, adapted to pierce and penetrate the skin, is of metal.

3. An integral hypodermic needle as in claim 1, wherein the hollow tubular body is of a synthetic resinous material, and the end portion compris? ing the sharp edged point, adapted to pierce and penetrate the skin, is of a relatively hard synthetic resinous material containing glass fibers therein as a reinforcing agent.

4. An integral hypodermc needle als in claim 1,

6 wherein the hollow tubular body is of a synthetic resinous material, and the end portion comprising the sharp edged point, adapted to pierce and penetrate the skin, is of a relatively hard ySynthetic resinous material, said resinous end portion having its piercing point reinforced by metal electrolytically deposited thereon.

JACOB A. SAFFIR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 387,454 Siegenthaler Aug. 7, 1888 722,203 Brooke Mar. 10, 1903 1,470,981 Ingalls Oct. 16, 1923 

